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| Author(s): |
Christiane França Camargo Stabe
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Faculdade de Ciências Médicas |
| Defense date: | 2012-10-24 |
| Examining board members: |
Bruno Geloneze Neto;
Dennys Esper Cintra;
Laura Sterian Ward;
Ana Maria Pitta Lotemberg;
Sandra Regina Vívolo
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| Advisor: | Bruno Geloneze Neto |
| Abstract | |
Background: Upper body subcutaneous adipose tissue, estimated by neck circumference (NC), is associate with cardiovascular risk factors, as well as visceral abdominal fat, which is usually estimated by waist circumference (WC). There are few epidemiological population-based studies on the clinical significance of the NC relative to Metabolic Syndrome (MetS) and insulin resistance (IR). Objective: (1) To investigate the relationship of the neck circumference (NC) with insulin resistance (IR) and with metabolic syndrome (MetS) components in a large Brazilian sample, within a wide range of adiposity among non-diabetics and diabetics, and (2) establish cut-off points for the NC as predictor of MetS and IR. Design: This is a cross-sectional study. Subjects: 1,068 Brazilian adults, with 71.8% women aged between 18 and 60 years (mean age = 39.4 years). Measurements: Volunteeers with body mass index (BMI) between 18.5 to 40.0 kg/m2 (mean BMI = 27.3 kg/m2, men, 28.3 kg/m2, women), with normal glucose tolerance (n=762) or type 2 diabetes (T2DM) (n=306) underwent assessment of anthropometric measurements: waist (WC), hip, thigh and neck circumferences. The visceral abdominal fat was assessed by ultrasound. Insulin sensitivity (IS) was measured by hyperinsulinemic-euglycemic- clamp (10% of total sample, n=105), and also by calculating the HOMA-IR in the total sample. Correlation analysis, adjusted for age and BMI, were used to assess the association between anthropometric measures and IR and traditional and non-traditional MetS components, and plasma free fatty acids and adiponectin. Binary logistic regression analysis were used to assess the chance of developing IR or MetS according to the enlargement of NC and WC. ROC curves were used for gender-specific cut-off values for the prediction of IR and MetS. Results: NC was positively correlated with WC, in both genders. Also, NC showed a positive correlation with triglycerides, fasting glucose, fasting insulin, and H OMA-IR, and NC had a negative association with HDL. NC and IS showed a negative correlation. A significant correlation was demonstrated between abdominal visceral fat and NC. In binary regression, increased NC added by 1.13 times the odds of MetS in women only, and added in 1.21 and 1.20 times the chance of IR in women and men, respectively. In ROC curves, NC presented the largest AUC for IR in women (p < 0.001), while NC presented a large AUC for MetS in both genders. We established the following cut-off points for NC: among women, NC > 36 cm in men and the CP > 40 cm, indicated risk for IR and MetS. Conclusions: NC measurements are an alternative and innovative approach for determining body fat distribution. The NC is positively associated with MetS risk factors, IR, and abdominal visceral fat, with established cut-off values for the prediction of MetS and IR (AU) | |